30.11.2022
Nowadays, linear motion sequences are commonplace in many areas of automation, handling and testing technology. In handling technology, linear axes operate horizontally or vertically and, when combined modularly, are a guarantee for dynamic production processes.
In contrast, the precise measurement of forces during load tests or for the transmission of adjustable forces during static or dynamic material tests is a top priority in testing technology. In order to achieve exact measurement results, the equipment must be protected, for example, against disruptive assembly-related lateral forces.
Loewe GK Linear: High axial stiffness combined to high radial and angular displacement compensation
Applications for which the articulated couplings of the Loewe GK Linear range are the perfect choice. The strength of these axially stiff couplings lies in the accurate transmission of purely linear tensile and compressive forces while compensating for radial and angular displacements.
5 sizes for axial loads of up to 13.000 N
The range includes a total of 5 sizes with hub outer diameters from 27 mm to 100 mm, which can be used for 800 to 13.000 N maximum axial loads depending on the coupling size. The axially stiff couplings in this range offer a wide array of shaft connection options. They are available with internal threads, threaded pins, clamping hubs or in conjunction with the hub designs mentioned. The spectrum of thread sizes extends from M5 to M36 (internal thread - optionally with regular or fine thread) and M5 to M24 (external thread). 6 to 50-mm bore diameters are available for versions with clamping hubs.
High radial and angular displacement possibility
Depending on the size, the articulated couplings compensate for parallel and angular displacements of up to 2.5 mm and 3 degrees respectively.
The high-performance plain bearings used in the couplings feature high thermal resistance as well as excellent resistance to chemicals, such as organic solvents, oils and greases. As a result, the couplings can also be used for automation applications in higher temperature ranges.
Dynamics and precision in gantry systems
Electrically or pneumatically driven linear axes are the backbone of dynamic handling systems.
These are usually designed as gantry systems in order to carry out palletising and joining applications in a highly efficient manner.
For feeding applications, an axially stiff linear coupling was sought for connecting the linear motor runner to the slide of the axis. In such a case, the coupling should be able to compensate not only for the transmission of more than 600 N axial forces, but also for radial and angular displacements. The coupling was required to work precisely with high axial stiffness and low rotational inertia, in line with the high positioning accuracy and acceleration rates of the axis. The Loewe GK L 27 coupling is specifically intended for these demanding applications. Available for maximum axial loads of up to 800 N, it can compensate for radial and angular displacements of up to 1 mm and 3 degrees respectively. In order to meet high positioning accuracy requirements, this lightweight aluminium coupling has an axial stiffness of 16.000 N/mm. The linear coupling is equipped with a threaded bore and threaded pin size M8 for connection to the runner and slide.
High forces in load testing of materials
Servo-hydraulic test benches enable static and dynamic load tests on materials or determine the dynamic spring characteristics of elastic or polymer products. Test benches are usually force- and displacement-controlled and load the test process materials with adjustable forces.
Using a misalignment-compensating linear coupling, we were required to ensure, in one of these test benches, that loading occurs largely free of superimposed bending and lateral force stresses, and that the coupling can precisely transmit the generated forces at the same time. A Loewe GK L 100 coupling was used for this. The coupling, designed for axial loads of up to 13.000 N, enables up to 2.5 mm radial displacement compensation and max. 3-degree angular displacements. With its 61.500 N/mm high axial stiffness, it ensures precise transmission of the forces exerted for material testing in the test bench. The linear coupling is connected through hubs with size M30 internal threads on both sides.